Another cones need to id.

[dave r]

The white shell is definitely eburneus, it is the wrong shape and has the wrong spots for any of the others you mention. As to the other, it  really is too worn to identify, in that condition it could be one of many species. If I were to hazard a guess I woud say something like striatellus or circumactus, onre of that complex of cones. But as I said it is really too worn and also very juvenile.
Dave